Advances in video technology have allowed users to view video data on an ever increasing number of devices and platforms. The desire to view video data on small platforms and the need to decrease the bandwidth for transmitting video data has lead to the development of different encoding formats that, among other things, substantially compress the video data. Video data can now be transmitted to and stored on mobile telephones and other small platforms; and extended-length movies can now be stored on lower-density video discs.
Many of these different video formats are not directly compatible. For example, video data encoded in the Advanced Video Coding (“AVC”) format cannot be directly played on a video player configured for playing video in the Moving Picture Experts Group 2 (MPEG-2) format. Some prior art systems use transcoders to (1) translate the video data encoded in the AVC format (“AVC video data”) into raw pixel data and then (2) translate the entire raw pixel data into video data encoded in the MPEG-2 format (“MPEG-2 video data”). Using the prior art systems, video data encoded in one format can be later played on a system configured to play video data in another format.
FIG. 1 shows one such prior art system 100. The system 100 includes an AVC decoder 105 coupled to an MPEG-2 encoder 110 over a channel 115. The AVC decoder 105 translates AVC video data into raw pixel data, which is transmitted over the channel 115 to the MPEG-2 encoder 110. The MPEG-2 encoder 110 then translates the raw pixel data into MPEG-2 video data, which can then be played on an MPEG-2 compatible device.
The solution provided by the system 100 has several disadvantages. First, the process performed by the system 100 is time consuming: it requires that the AVC video data be entirely translated into raw pixel data, resulting in a large block of raw pixel data that must all be translated into MPEG-2 video data. Second, the process requires a lot of memory: it must store much of the raw pixel data while, for example, predictive frames are generated.